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weak service drop attachment


John Dirks Jr

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I had a treetop land on my service cable one time and it jerked the insulator (we call them Emily knobs) right off the house. The mast popped out of the clamp on top of the meter box. But there was no real damage done. One of the guys from the power Company said that was the way to go. A weak link there can prevent a break in the cable.

As Charlie said, that appears to be a proper hookup, although the wire usually doubles back to the clamp on the ones I see.

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Hi,

Actually, although it is a "proper" device, I don't think that what you are seeing is proper. It's a messenger feed-through clamp and those must have two wires stretching back from the insulator to the clamp.

Around here, they use a thin coated cable that extends to the insulator. You put the end of the loop around the insulator, thread the free end through the end and then cinch it down tight on the insulator. The free end has a wedge-shaped block that is then inserted into the feed-through clamp sleeve, the messenger cable is adjusted to the length they want and then the other end of the messenger is anchored. The strain of the weight of the messenger, plus the weight of the other two or three hots wrapped around the messenger, pulls the wedge tightly into the receiver and tightens its grip on the end of the bare messenger.

Sometimes I see ridgid ones like that illustrated below; but in every case there is always two strands extended from the feed-through clamp to the insulator - either right next to each other or separated by however thick the insulator is, as in the illustration below.

It looks like one side of that anchor snapped and, if I'm seeing it correctly, they bent the broken end around the other side right there against the insulator.

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By the way, I'm feeling a little bit like a proud daddy right now, 'cuz, just about every way I searched for an illustration of a feed through drop attachment on google, the Army electrical correspondence course in TIJ's reference library popped up - most of the time in only second place. That's where the photo above came from; I'd completely forgotten to look in the reference library first before I started googling.

That's kind of a testament to our posting policy here because, by trying to keep technical subjects on-topic and not cluttered with a lot of other stuff that's unrelated to the topic at hand, our resources are more available to all inspectors with just a very simple search.

ONE TEAM - ONE FIGHT!!!

Mike

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It looks like one side of that anchor snapped and, if I'm seeing it correctly, they bent the broken end around the other side right there against the insulator.

ONE TEAM - ONE FIGHT!!!

Mike

I agree but I had no idea what to call the clamp.

You sharp eye beat my quick look on the way out of town. Good catch and you're right. The library is a great resource.

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  • 2 weeks later...

Happened to think about this thread today while I was up on a roof and took a few snaps of one of the clamps I described above. It's the most common type of service drop feed-through clamp I see here.

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ONE TEAM - ONE FIGHT!!!

Mike

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